Method of peritoneal dialysis

ABSTRACT

A method for manufacturing and using a dialysis collection bag for peritoneal dialysis treatment, and the dialysis collection bag itself. A collection bag is fabricated with a sterilization tablet therein, having a soluble coating over a sterilization agent. When the collection bag is filled with used dialysis solution at the completion of the dialysis therapy, the soluble coating dissolves over a known period of time such as about 30 minutes. The delayed dissolution allows time to take a specimen sample of the unadulterated used dialysis solution. When the dissolution of the coating is completed, the tablet releases the sterilization agent to sterilize the used dialysis solution, so that pathogens are destroyed to prevent the transmission of disease in the event the collection bag is disposed of improperly.

CROSS-REFERENCE TO RELATED

This application is a continuation-in-part of U.S. patent applicationSer. No. 08/196,973 filed Feb. 14, 1994 now U.S. Pat. No. 5,527,272.

FIELD OF THE INVENTION

The present invention relates to the field of medical dialysis includingperitoneal dialysis and hemodialysis. In particular, the presentinvention relates to a dissolving bacteriocidal additive to a fluidcollection bag to sterilize the fluid collected in the bag for safedisposal of the sterilized fluid.

BACKGROUND OF THE INVENTION

The common treatment for renal failure is hemodialysis treatment orperitoneal dialysis treatment. Both treatments utilize the diffusion ofliquid through a semipermeable membrane. In the case of hemodialysis themembrane is in a dialyzer external to the patient, so that blood iswithdrawn from the patient's vascular system and passed across themembrane while dialysis solution is passed across the other side of themembrane. Impurities in the blood are drawn through the membrane byosmotic pressure on the membrane and are disposed of in the discardeddialysis solution. In the case of peritoneal dialysis, the semipermeablemembrane is the patient's peritoneal membrane. Dialysis solution isintroduced into and retained for a period of time in the peritonealcavity, and impurities in the blood migrate through the peritonealmembrane and into the dialysis solution. The dialysis solution with theimpurities is then withdrawn from the peritoneal cavity and discardedinto a "drain" bag or "collection" bag.

Both hemodialysis and peritoneal dialysis require significant amounts ofdialysis solution, sometimes called dialysate. Common dialysates areprimarily water, but with low ionic concentrations of dissolved sodium,potassium, calcium, magnesium, chloride, acetate, glucose andbicarbonate. The proportions of these and other compounds depends on avariety of factors. Regardless of the exact concentrations and relativeproportions of the dissolved compounds, the main material in alldialysates is water.

Dialysis solutions have been premixed and prepackaged in a variety ofmixes and sizes, so that the patient or the medical professional simplyselects the desired size and mix of dialysate, makes the appropriatetubing connections to the prepackaged dialysates and to the patient andthe dialysis machine, and then commences the procedure.

Regardless of the type of dialysis--peritoneal dialysis orhemodialysis--the procedure results in significant and sometimessubstantial quantities of spent dialysis solution. This used dialysissolution has been exposed to and often contains a variety of pathogensincluding infectious diseases. There are cases in which used dialysissolution was found to contain viable HIV virus, for example, and thereare undoubtedly other instances where used dialysis solution containedbacteria or viruses of other diseases as well.

This used dialysis solution is normally deemed "medical waste" and isrequired to be disposed of in accordance with applicable medical wastedisposal procedures so as not to spread disease or contaminate watersupplies. However, it is commonly recognized that the used dialysissolution is often disposed of improperly. Because many dialysisprocedures are adapted for the convenience of home use, used dialysissolution is sometimes improperly discarded by simply putting it intotrash receptacles for ordinary trash pick-up or pouring it into a sinkor flushing it down the toilet. Even in hospitals and clinics, the highcost and inconvenience of medical waste disposal may tempt professionalsto dispose of used dialysis solution improperly.

In the field of urinary catheters, there is a body of art pertaining topreventing pathogens from migrating from a urine collection bag upthrough a catheter and into the urethra. Such art is not directed towardthe sterilization of the collected urine so that it can be properlydisposed of without infecting others since urine does not normallycontain infectious diseases even if from a diseased patient. Instead,this art is more directed toward preventing the collection bag frombecoming a colonization site from which infection can migrate up thecatheter to the patient himself. Illustrative of this urinary catheterart are U.S. Pat. Nos. 4,529,398 by Wong; 4,661,100 by Rechsteiner;5,267,989 by Moyet-Ortiz; 4,863,445 by Mayhan; 4,417,892 by Meisch; and4,372,313 by Villari.

The typical approach to preventing urinary tract infections in theurinary catheter prior art mentioned above is to include a sterilizingagent in the catheter or in the collection bag so that pathogens cannotmigrate up the catheter. Such an approach is not appropriate for adialysis collection bag, however, because in dialysis it is oftendesired to take specimen samples of the used dialysate. If the dialysateis sterilized upon entering the collection bag, then specimen samplescannot be cultured to test for live pathogens. It is also desirable indialysis that the collection bag be entirely self-contained, so that thecollection bag is manufactured with the sterilizing agent pre-placedwithin it to avoid a separate placement step at the time of use.

In the Wong patent, a dispensing device having a polymer with achemoprophylactic agent is placed within the collection bag. Thedispensing device begins sterilizing liquid in the collection bagimmediately upon contact, and the device is designed such that thesterilizing properties continue for an extended period of time. Incontrast, in dialysis collection bags it is desirable that thesterilization of the liquid not be commenced immediately upon contactwith the dialysis collection bag, and in dialysis collection bags it isnot necessary that the sterilization be contained for an extended periodof time because the bag is filled in a very short period of time ratherthan over a period of many hours.

The Rechsteiner patent discloses a system with a urine collection baghaving a fragile resinous material inside which is broken to release asterilizing or diagnostic agent. The Rechsteiner patent is like the Wongpatent in that it is designed for urinary catheter applications in whichthe collected urine must be sterilized immediately upon contact and overan extended period of time to prevent pathogen migration into thepatient. The Mayhan patent is similar to the Rechsteiner patent, exceptthat the resinous sterilizing agent is replaced with a slow-dissolvingtablet. The Moyet-Ortiz patent discloses an antiseptic absorbent pad ina urine collection device; the Meisch patent discloses an outlet tube toa urine collection bag which is treated with a sterilizing agent toprevent pathogen colonization; the Villari patent discloses a urinecollection bag with a tubular portion having a device for retaining anantimicrobial agent.

SUMMARY OF THE INVENTION

The present invention includes a dialysis collection bag and method ofusing the same in dialysis treatment and the disposal of used dialysisfluid. The apparatus of the invention includes a used dialysatecollection bag having a sterilizing tablet within the collection bag.The sterilizing pill is coated with a gelatinous coating to delay thedissolution of the pill when the collection bag is filled.

In an alternative embodiment, the present invention includes a useddialysate collection bag and a sterilization bag connected thereto. Thesterilization bag contains a sterilizing agent and is attached to thecollection bag by a breakable connection. Once the connection is broken,there is fluid communication between the collection bag and thesterilization bag.

The system is operated by performing peritoneal dialysis in theconventional manner, including the step of draining the used dialysissolution into the collection bag. In one embodiment, the used dialysissolution begins to dissolve the gelatinous coating on the sterilizationtablet immediately upon entering the collection bag. However, thegelatinous coating on the sterilization tablet is such that the tabletdoes not release the sterilization agent for about 30 minutes after theinitial contact between the used dialysis solution and the sterilizationtablet. This 30 minute delay allows time for a specimen sample to betaken from the collection bag before the sterilization agent is releasedto sterilize the used dialysis solution. Once the approximately 30minutes expires so that the gelatinous coating is dissolved and thesterilization agent is released from the sterilization tablet, thesterilization agent is completely released, substantially immediately.In an alternative embodiment, when the sterilization agent is containedin a sterilization bag attached to the collection bag by a breakableconnector, once the collection bag has been filled and samples taken theconnection between the two bags is broken and the sterilization agent iscompletely released into the dialysis solution. In either embodiment,unlike in the case of urine collection bags used with urinary catheters,there is no need for slow and prolonged release over a period of time.The collection bag with sterilized used dialysis solution is disposed ofin the standard proper manner as medical waste, but in the event thatthe disposal is improper for some reason, there is now much lesslikelihood of spreading infectious disease.

A variety of sterilization agents and gelatinous coatings are feasiblefor the sterilization tablet. In a preferred embodiment, thesterilization agent is calcium hypochlorite and the coating is sodiumlaurel sulfate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a dialysis collection bag inaccordance with the present invention.

FIG. 2 shows a perspective, partial cut-away view of a sterilizationtablet in accordance with the present invention.

FIG. 3 shows a perspective view of an alternative embodiment of theinvention, showing a sterilization bag attached to the dialysiscollection bag by a frangible seal.

DETAILED DESCRIPTION OF THE INVENTION

A perspective view of a dialysis collection bag in accordance with thepresent invention is shown in FIG. 1. A dialysis collection bag 10 is abag-shaped element connected to a drain tube 12 which is connected to anordinary peritoneal dialysis or hemodialysis tubing set (not shown). Thecollection bag 10 is sealed so that it is liquid tight and liquid cannotenter or leave it except through the drain tube 12. The collection bag10 is constructed from plastic sheet material in the conventional mannerknown in the art and is sized appropriately so that the collection bagalone or in combination with a collection bag set has sufficientcapacity to receive the used dialysis solution from a dialysistreatment.

Inside the collection bag 10 is a sterilization tablet 14. Thesterilization tablet 14 is preferably placed within the collection bag10 at the time the collection bag is being manufactured. Thesterilization tablet 14 is placed in the collection bag 10, and then thecollection bag 10 is sealed to retain the sterilization tablet 14therein. In a preferred embodiment, the tablet contains calciumhypochlorite. Other disinfectant agents are feasible as well, includinglithium hypochlorite, sodium hypochlorite, and powder chloramines suchas sodium p-toluene sulfonchloramide or other soluble disinfectants. Thequantity and concentration of disinfectant should be sufficient toquickly disinfect 2-4 liters of used dialysis solution contained withinthe collection bag.

An important aspect of the preferred embodiment of the invention is theuse of a dissolving coating 16 over the body 18 of the sterilizationtablet 14 as shown in FIG. 2. The coating must be dissolved by contactwith the used dialysis solution before the disinfectant in thesterilization tablet 14 is released. As explained above, this delays theactivation of the sterilization tablet 14 for a short time after initialcontact with the used dialysis solution, to allow time to take aspecimen sample before the disinfecting process commences. It has beenfound that the most convenient time period to provide between theinitial contact between the sterilization tablet 14 and the useddialysis solution, to allow for the collection of a specimen sample, isabout 30 minutes. In a preferred embodiment, the coating takes at least30 minutes to dissolve.

The coating 16 in the preferred embodiment is sodium laurel sulfate orgelatin. Other coatings are also feasible to provide appropriate delayin activation of the sterilization tablet 14, including ethylcellulose,hydroxypropyl-methylcellulose, titanium dioxide, sucrose stearate,hydroxypropylcellulose, polyvinyl-acetaldiethylaminoacetate, or acryliclatex sprays. The coating should dissolve in a pH range of 3-10.

The drain tube 12, as well as the rest of the tubing set and thecollection bag 10 as well, may be sterilized at the time of manufactureby processes known in the art. Such processes include but are notlimited to the use of ethylene oxide gas, steam, gamma rays and electronbeams.

The manufacturing method will normally include the fabrication andassembly of the tubing set with its various elements such as valves,clamps and so on; the construction of the collection bag 10 with thesterilization tablet 14 therein; the attachment of the collection bag 10to the drain tube 12; and the sterilization of the entire assembly byone or more of the known means mentioned above. The assembly is used inperitoneal dialysis and hemodialysis procedures much like tubing sets ofthe prior art. When the collection bag 10 is filled with used dialysissolution, the coating 16 to the sterilization tablet 14 begins todissolve. The time it takes for the coating 16 to dissolve to the pointwhere the sterilization agent is released may vary, as mentioned above,from a few seconds to an hour or longer. Preferably, the time is atleast a few minutes, in order to allow time for a specimen sample to betaken, and the time is not so long that the used dialysis solution maybe removed from the collection bag 10 prior to being sterilized byrelease of the sterilization agent. It has been found that about 30minutes is ideal for this time period.

Once any desired specimen sample has been taken, and the coating 16 tothe sterilization tablet 14 is dissolved so that the sterilization agentis released from the sterilization tablet 14 to sterilize the useddialysis solution, the collection bag 10 with the used, sterilizeddialysis solution therein is discarded. It is still desirable that thecollection bag 10 with the used, sterilized dialysis solution therein bediscarded as medical waste, in accordance with proper medical wastedisposal procedures. However, the prior sterilization of the useddialysis solution provides some assurance against the spread of diseasein the event that such procedures are ignored or followed improperly.

With reference now to FIG. 3, an alternative embodiment of the presentinvention is readily understood. In this embodiment, a sterilization bag20 is attached to the collection bag 10 by a frangible seal 22 whichseparates the bags. Preferably, the sterilization agent will be placedwith the sterilization bag 20 when the sterilization bag and thecollection bag are being manufactured. As mentioned previously, thequality and concentration of disinfectant contained within thesterilization bag 20 should be sufficient to quickly disinfect 2-4liters if used dialysis solution contained within the collection bag 10.A sealing device, preferably of the heating type, will be employed toseal the walls of frangible seal 22 so that the sterilization agent isseparate from the initially empty collection bag 10. The frangible seal22 is readily delaminated to permit the free flow of materials betweenthe containers while securing the containers to each other.

As described herein, peritoneal dialysis is performed on a patient andthe used dialysis solution is collected in the collection bag 10. Whilethe dialysis solution is collected and the collection bag 10 is filled,any desired specimen samples may be taken. Once the desired specimensamples have been taken, the frangible seal 22 between the collectionbag 10 and the sterilization bag 20 is broken, providing free flow ofmaterials between the compartments. The used dialysis solution issterilized substantially immediately. The sterilization bag 20 and thecollection bag 10 with the used dialysis solution therein are discarded.

What is claimed is:
 1. A method of peritoneal dialysis, comprising:engaging with a dialysis patient a dialysis tubing set including adialysis solution source and a collection bag having a sterilizationdevice therein, wherein the sterilization device includes asterilization tablet with a coating; performing the dialysis on thepatient using the dialysis solution; draining the used dialysis solutioninto the collection bag; and sterilizing the used dialysis solution withthe sterilization device in the collection bag; wherein thesterilization step includes dissolving the coating with the useddialysis solution before releasing the sterilization agent.
 2. Themethod of claim 1, wherein the sterilization agent is a solubledisinfectant.
 3. The method of claim 2, wherein the sterilization agentis selected from the group consisting of calcium hypochlorite, lithiumhypochlorite, sodium hypochlorite and powder chloramines.
 4. The methodof claim 2, wherein the coating is selected from the group consisting ofsodium laurel sulfate, gelatin, ethylcellulose,hydroxypropylmethylcellulose, titanium dioxide, sucrose stearate,hydroxypropylcellulose, polyvinyl-acetaldiethylaminoacetate and acrylic.5. The method of claim 2, wherein the coating takes at least thirtyminutes to dissolve.
 6. A method of peritoneal dialysis, comprising:engaging with a dialysis patient a dialysis tubing set including adialysis solution source and a collection bag having a sterilization bagattached by a frangible seal thereto, the sterilization bag containing asterilization agent therein; performing the dialysis on the patientusing the dialysis solution; draining the used dialysis solution intothe collection bag; breaking the seal between the collection bag and thesterilization bag causing fluid communication therebetween; andsterilizing the used dialysis solution with the sterilization agent inthe sterilization bag.
 7. The method of claim 6 wherein said frangibleseal is a heat seal and said step of breaking the seal includesrupturing said heat seal to allow flow between the sterilization agentand used dialysis solution through the rupture.